package com.rnyoudaiapp.util.encryptutil;

import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;


public class AESCipher {

	private static final String IV_STRING = "A-16-Byte-String";
	private static final String charset = "UTF-8";

	public static String aesEncryptString(String content, String key) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
		byte[] contentBytes = content.getBytes(charset);
		byte[] keyBytes = key.getBytes(charset);
		byte[] encryptedBytes = aesEncryptBytes(contentBytes, keyBytes);
		Base64.Encoder encoder = Base64.getEncoder();
		return encoder.encodeToString(encryptedBytes);
	}

	public static String aesDecryptString(String content, String key) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
		Base64.Decoder decoder = Base64.getDecoder();
		byte[] encryptedBytes = decoder.decode(content);
		byte[] keyBytes = key.getBytes(charset);
		byte[] decryptedBytes = aesDecryptBytes(encryptedBytes, keyBytes);
		return new String(decryptedBytes, charset);
	}

	public static byte[] aesEncryptBytes(byte[] contentBytes, byte[] keyBytes) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
		return cipherOperation(contentBytes, keyBytes, Cipher.ENCRYPT_MODE);
	}

	public static byte[] aesDecryptBytes(byte[] contentBytes, byte[] keyBytes) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
		return cipherOperation(contentBytes, keyBytes, Cipher.DECRYPT_MODE);
	}

	private static byte[] cipherOperation(byte[] contentBytes, byte[] keyBytes, int mode) throws UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
		SecretKeySpec secretKey = new SecretKeySpec(keyBytes, "AES");

		byte[] initParam = IV_STRING.getBytes(charset);
		IvParameterSpec ivParameterSpec = new IvParameterSpec(initParam);

		Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
		cipher.init(mode, secretKey, ivParameterSpec);

		return cipher.doFinal(contentBytes);
	}

	public static void main(String[] args) {
		String aa = "36xGtHdYy1Rl3bXltoAzOg==";
		try {
			String bb = AESCipher.aesDecryptString(aa, "fe0r2mwnDfoiDl6L");
			System.out.println(bb);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}